The use of omega-3 supplements has been used to effectively treat major depression, according to a recent study (published in the Journal of Clinical Psychiatry). While the benefits of omega-3 have been well documented (a diet rich in omega-3 is good for your heart, as well as your brain) the study is the largest of its kind to demonstrate a clear link between omega-3 supplementation and depression. Previous studies have suggested that individuals with a deficit in certain omega-3s may be predisposed to depression.